Generally, submersible pump potheads are male electrical connectors used in oil wells. After connecting a pothead with submersible pump electrical cable, the cable conductors and the pothead pins or contacts must be electrically tested. The tests may be conducted under laboratory conditions; however, it is often necessary to test the connection at the field site. Various tests are usually conducted, including an insulation resistance test, a DC voltage test to measure microamp leakage and an AC voltage test to measure milliamp leakage.
Some potheads have metallic faces from which the contacts extend. When the conductors and contacts are electrically tested, flashover may occur between the contacts and the pothead face if the contacts are not insulated.
Typically, to insulate the contacts, a silicon test fixture is filled with clean, highly insulating dielectric silicon oil. The pothead is submersed within the filled fixture before electrically testing the connection between the contacts and conduit cable. Although this method works adequately in a laboratory setting, problems arise, such as damage to the pothead cable due to bending, when performing the tests in the field under much more adverse conditions.
Some pothead faces are molded from rubber, thereby eliminating the need to submerse the pothead in the silicon fixture during testing. However, these potheads are limited to a single use. They cannot be reused after being submersed in an oil well, even if submersed for only one day, because of oil swell to the rubber.